Seam Register and Full-surface Printing Technology for 360-degree Flexo Shrink Sleeve
This technical paper solves 360-degree circumferential full-surface printing seam register defect of shrink sleeves, analyzes longitudinal splicing seam alignment difficulty, and introduces seamless virtual splicing flexo printing technology for integral shrink sleeves.
360-degree full-surface shrink sleeves require seamless circumferential printing without visible splicing seam for integral bottle packaging appearance. Traditional flexo roll printing has inevitable longitudinal web splicing seam, which will form obvious straight white seam after sleeve thermal shrinking, destroying overall full-surface packaging aesthetic effect.
Longitudinal seam cumulative register error is the core difficulty of full-circle shrink sleeve printing. Tiny position deviation of printing seam will be amplified after high-rate transverse shrinkage, forming wider visible white seam. The seam alignment accuracy needs to be controlled within 0.05mm to realize invisible splicing effect after shrinking.
High Speed Flexo Printing Machine - Stack Flexo Flexo Printing Machine
Virtual seamless splicing printing technology for shrink sleeve flexo presses. The servo system carries out seamless phase docking of printing patterns at web splicing position automatically, compensating pattern gap generated by physical web joint. After thermal shrinkage, the splicing gap is completely covered by pattern docking without visible white seam on sleeve surface.
Inner surface reverse printing exclusive process for shrink sleeves. Most shrink sleeves adopt inner reverse printing mode, with printed ink layer attached to bottle surface after shrinking to protect patterns from external friction damage. Reverse printing needs mirror image pattern design and reversed register parameter setting different from front surface conventional printing.
Anilox roller ink layer optimization for smooth sleeve surface. Shrink sleeve film has super smooth surface with no ink absorption capability. Thin uniform ink layer controlled by high-line anilox roller avoids surface ink mottle and ensures high-gloss finished sleeve appearance after shrinking.
Finished sleeve winding tension gradient control. Adopt gradual decreasing tension from winding core to outer roll to prevent inner roll excessive compression leading to advance shrinkage. Gradient tension winding keeps original sleeve film size stable during storage and transportation before thermal labeling process.
